Seismic analysis EC8

Question

Hi guys, 
 I' m trying to make a seismic analysis, using the response spectrum (EC8) from the "load item" list. 
 In the second phase I' m define one spectrum in x and y direction (direction parameters 1 and 0,3), specifying the masses (selfweight, live and dead loads in x and y) in the reference loads definitions 
 Unfortunatelly i' m not getting the right results. 
 Anyone know how to procede to make a seismic analysis following the EC8? 
 Thanks

Modestas · Answer

You should create a reference load with a Mass type selected and provide the masses in all 3 global directions.

Modestas · Answer

Your reference load definition should look like that: 
 LOAD R1 LOADTYPE Mass TITLE mass 
 SELFWEIGHT X 1 LIST ALL 
 SELFWEIGHT Y 1 LIST ALL 
 SELFWEIGHT Z 1 LIST ALL 
 MEMBER LOAD 
 13 TO 18 UNI GY 3 
 13 TO 18 UNI GY 1 
 13 TO 18 UNI GX 3 
 13 TO 18 UNI GZ 3 
 13 TO 18 UNI GX 1 
 13 TO 18 UNI GZ 1 
 END DEFINE REFERENCE LOADS 
 
 If that still does not help, please illustrate your issue with a screenshot.

Modestas · Answer

The responses obtained from the Response Spectrum analysis are absolute unsigned quantities. If you want to see signed bending moment diagrams, you can use either Dominant or Signed option in the Response Spectrum Load Case settings. You can find some more useful information on this topic here: https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/123938/signed-response-spectrum/376619#376619